fix: log interpretWriteTurn failures instead of silently falling back

The catch block and Zod parse failure both returned fallbackInterpretation
with no logging, making it impossible to diagnose why the LLM call was
being skipped. Now logs the Zod error or exception details before falling
back.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: MaxLinCode

apps/web/src/lib/server/interpret-write-turn.ts

@@ -18,11 +18,19 @@ export async function interpretWriteTurn(
     const parsed = rawWriteInterpretationSchema.safeParse(raw);
 
     if (!parsed.success) {
+      console.error("interpret_write_turn_parse_failed", {
+        zodError: parsed.error.format(),
+        rawOutput: raw,
+      });
       return fallbackInterpretation(input);
     }
 
     return normalizeRawWriteInterpretation(parsed.data, input.currentTurnText);
-  } catch {
+  } catch (err) {
+    console.error("interpret_write_turn_error", {
+      error: err instanceof Error ? err.message : String(err),
+      stack: err instanceof Error ? err.stack : undefined,
+    });
     return fallbackInterpretation(input);
   }
 }